In Vitro Study of Antibacterial and Antifungal Activity of Spirulina Platensis

Abstract

The blue- green microalgae (cyanobacteria) Spirulina are found naturally in saline lakes and rivers in tropical regions, and has been found to be effective in boosting the immune system and is rich in proteins(60- 70% of dry weight). We studied a sample of Spirulina platensis originally obtained in wild from a river in DR Congo, and artificially cultivated in GOMA/DRC by Antenna Technologies Grands Lacs Projects. The Spirulina obtained from the culture in our laboratory using available ingredients and controlling physical and physico- chemical parameters, contained approximativelly the same proportion in chemical components as the given ones by the literature review. The result of phytochemical screening showed that the powder of Spirulina platensis contains some active ingredients, such as tannins, terpene-sterols and saponosides. We also found high concentrations of total proteins from all fractions sampled. The results of biological tests showed that the proteinic extract of this alga was effective in inhibiting Shigella flexneri, Salmonella typhi and Salmonella B, and Candida albicans. The hydroethanolic extract was effective in inhibiting E. coli, Bacillus sp., Salmonella typhi, Salmonella B., Shigella frexneri, and Candida albicans. The tannic extract was effective in inhibiting Salmonella typhi, Shigella flexneri Candida albicans and Staphylococcus aureus. The fraction of terpene- sterols was effective against Shigella flexineri and Candida albicans. This algal species is a potentially source of nutrition for human health, as well as an important resource for fighting bacterial infections in human. The culture of Spirulina and the study of its combination to other antibiotics represent a potentially important economic and public health resource for Rwanda and the region.